Abstract
Abstract: :
Purpose: Visual impairment often occurs in children with cerebral palsy (CP). The aim of this study was to compare grating acuity deficit and amblyopia, to levels of motor impairment in children with spastic CP. Methods: Best corrected monocular grating acuity was measured in 163 children with spastic CP, and normal fundi, using the NuDiva sweep-VEP system. Acuity deficit was determined in octaves comparing visual acuity (VA) scores with mean normative data. Interocular acuity differences ≥ .13 logMAR were considered to indicate amblyopia. Patients were classified into 4 age groups (I – 6-12 mos; II – 13-24 mos; III – 25-36 mos; IV – 37-48 mos) and 3 motor-deficit groups (tetraplegic – n=67, diplegic – n=56 and hemiplegic – n=47). Motor impairment severity was classified into five levels by the Gross Motor Function Classification System (GMFCS). Results: 71% of the tetra-, 64% of the di- and 17,5% of the hemiplegics had VA below the normal limits. A high correlation was found between GMFCS and VA deficit: .74 for hemi- .89 for di- and .94 for tetraplegics. Amblyopia was found in 15% of the tetra-, 21% of di- and 9% of hemiplegics, without differences between groups (p=.30). The most frequent type of amblyopia was strabismic. Mean VA deficits in octaves were: tetraplegics (groups I: 1.41; II: 1.46; III: 1.09; IV: 1.31), diplegics (groups I: 1.26; II: .97; III: 1.08; IV: .82) and hemiplegics (groups I: .53; II: .72; III: .4; IV: .3). The tetraplegics were different from the hemiplegics in age group II (p=.03); in age groups III (p=.007) and IV (p<.001) tetra- and di- differed from hemiplegics. Conclusions: Spastic CP children have cortical VA deficits that are progressively greater in hemi-, di-, and tetraplegics and are proportional to the degree of motor impairment classified by the GMFCS.